Speculation slower growth in hiring will extend Federal Reserve stimulus lifted U.S. stocks and pushed the annual advance in the Standard & Poor’s 500 Index within a percentage point of the best yearly gain in a decade.

U.S. stocks fell, erasing earlier gains, as Secretary of State John Kerry said the president will hold Syria’s government accountable for using chemical weapons. Treasuries held onto earlier gains triggered by a drop in durable goods orders.

Stock splits are losing their allure with American executives amid one of the broadest rallies ever, sending the number of shares trading above $100 to a record and showing the rising dominance of institutions in equity markets.

In April 2008, three months before drug makers Elan Corp. and Wyeth were scheduled to release results of their Alzheimer’s drug trial, two health-care analysts for hedge-fund manager Steven A. Cohen warned their boss in an e-mail that a doctor, who implied he had seen inside information about the trial, said it wasn’t going well.

Microsoft Corp. tumbled the most in five months after Goldman Sachs Group Inc. said personal- computer market-share losses are accelerating and its push into consumer electronics hasn’t gained traction.

The largest U.S. companies are beating the average stock in the Standard & Poor’s 500 Index by the most in more than a decade, fueled by rising dividends, valuations 31 percent below the historical average and fear.